Introduction: How to Create Programs on a Graphing Calculator

Ever wish that you could have a program on your calculator to do long drawn out formulas for you? With this tutorial you will be able to program formulas into your calculator with ease.

This is for anyone who wants an easier human-error proof way to derive the answer to several formulas. It is especially handy for those among us who are engineers and don’t want to do computation by hand.

You can program any formula that uses inputs into your calculator using this process. You can program formulas such as the formulas for Reynold’s Number, the Quadratic Formula, Antoine’s Equation, the volume of a sphere, Pythagorean Theorem; the possibilities are endless. For demonstration purposes I will be using the coding for the quadratic formula.

**At the bottom of the instructions I have an "If you messed up really badly" section that should be noted here just in case you find yourself in a dark abyss with your program and don't know where else to turn.**

What You Will Need

-A TI-83 or TI-84 plus calculator (these instructions may work for other calculators as well)

-A copy of your specific formula

-A previously calculated answer for your formula so that you can test out your program to see if it is working correctly

Step 1: Familiarize Yourself With Specific Keys

I have outlined several keys that you will be using during this process. I have only highlighted the ones that I feel are used most frequently in this tutorial those that are harder to find. I think it is safe to assume that most are calculator savvy and know where to find keys such as “ENTER” and “CLEAR”.

Step 2: Give Your New Program a Name

Push the PRGM (program) button.

Using the right arrow key, scroll over to the tab that says “NEW”.

Press ENTER.

Type in the name you want your program to be ( Since the calculator automatically locked the keys on alpha you don’t have to push ALPHA every time you want to add another character but you will have to later on) .

I am making my program name my initials: SEK

Step 3: Find the Menu I/O

Press ENTER after you are done inputting your formula’s name.

Press PRGM .

Using the right arrow key scroll over to I/O.

Step 4: Type in the Variables for Your Formula

Select prompt by pressing 2 on your ten key pad.

Type in the variables that you will include in your formula. You will have to press ALPHA every time for each new character. Separate the variable with a comma (button right above the 7) and once you are done press ENTER.

Step 5: Type in Your Actual Formula

Now it’s time to type in your formula. Remember to include your variables by pressing alpha beforehand. If you mess up, don’t worry just scroll over the letter and press DEL (delete which is 2 buttons right of the 2nd button).

Once you are done typing the formula, press STO-> (1 button above the ON button). This will allow you to set your formula equal to a value such as X. After that press ENTER.

If you have more than one line of information for your formula, simply press ENTER, which will start the next line of code beginning with a colon (:). You can store the second value as another variable such as Y as seen below for the quadratic formula.

Step 6: Find Disp Under I/O Menu

Press PRGM, scroll over to I/O and select Disp (display) by pressing 3 on the 10 key pad. Disp is how you want your answer to be displayed.

Step 7: Tell Your Calculator What Your Outputs Are

If you have just one output you can write whatever variable you assigned your formula to equal immediately after Disp.

If you have 2 outputs press ALPHA then (+) to input quotations. Press ALPHA then zero on the ten key pad for a space. Do this 12 times. Your cursor should land right under the “s” in Disp on the line above.

Step 8: Tell Your Calculator How You Want Your Function Displayed

Press ALPHA then X or whatever variable you want your function to be assigned to.

Step 9: Find the Equals Sign

Type in an equal sign by pressing the 2nd button and then the MATH button (2 buttons below the 2nd button. Select 1 which is =.

After the equals sign type in “,X,Y (for those with 2 outputs in their formula)

Step 10: Test Your Program Out

Now you have finished the programming, but DO NOT PUSH CLEAR. Push 2nd MODE to get out of the screen you are on.

To use the program push PRGM and select the program you will want to use.

Press ENTER after you see your program’s name and the prompts will follow for what you want to input your values as. Press ENTER after each input and after your final input press ENTER and your answer should be displayed to the right of the screen.

This is the time to make sure that your calculated value is conclusive with the value that you had previously obtained by other means.

If you followed my example of the quadratic equation your ending result should look like what I have on the screen above.

Step 11: If You Messed Up Really Bad...

If you messed up you can always press PRGM, scroll over to EDIT and fix your errors.

If you messed up so badly that you want to delete your program push 2nd MEM (+)

Select Mem Mgmt/Del… by pressing 2

Select Prgm... by scrolling down or pressing 7.

Scroll down to the program you want to delete and press DEL.

You Will be prompted with a message asking “Are You Sure?” and if you are sure select YES by either scrolling and pressing ENTER or pressing 2.

Press 2nd MODE and you will exit that screen.

Step 12: Tips and Other Resources

Remember if you navigate to a screen that you don’t want by accident you can usually get back by pressing CLEAR.

Press the DEL key anytime you want to delete a single character. If you press CLEAR that will delete the entire line.

If you find yourself completely lost always remember to press 2nd MODE which is essentially “quit” for calculators. That will take you back to the main screen where calculations are done.

Your results are incorrect because the order of the numbers in the final step of testing the program is actually 1,3,2 not 1,2,3 (as in, A=1 B=3 and C=2). I had the same problem before I realized that I had read it wrong!